AMHERST, Mass. - The NBA preseason is meaningless, right?

That is, unless you haven't played in an actual game since March 1, 2014, as a freshman at Kansas and your career has been on the endangered list.

But on Tuesday night, Joel Embiid showed that his career can be reborn, assuming he can stay healthy. The 7-foot-2, 276-pounder finished with six points, four rebounds, two blocks and three turnovers in 12 minutes, 57 seconds of action in a 92-89 preseason-opening victory over Boston at the Mullins Center.

The Sixers selected Embiid third overall in June 2014, a few days after the first of two foot surgeries. There was a time when his participating on a five-on-five scrimmage let alone a game appeared to be wishful thinking. He even considered walking away from basketball after his brother was killed in an accident on Oct. 14, 2014, in his native Cameroon.

It's a good thing for the Sixers that he didn't.

Embiid looked the way one would expect him to look in first basketball game in more than two years.

The 22-year-old showed some rust, turned the ball over, and initially looked lost on defense. However, he showed glimpses of someone with all-star potential.

"At the beginning, I was pretty nervous," Embiid said. "I think I had trouble breathing, so it was hard. But once I got the first bucket, everything started to slow down. I saw the game easier.

"I just felt like I was myself again."

Embiid missed his first three shots before leaving the game with 7:44 left in the first quarter. He was a more comfortable player and had a different mind-set when he reentered the game at the 1:18 mark of the quarter.

His first basket came 28 seconds later on seven-foot fadeaway over Tyler Zeller. Then he blocked Jaylen Brown's dunk attempt 25 seconds later before hitting a 23-foot jumper with one second left in the quarter.

The Sixers took him out of the game at the 8:52 mark of the second quarter before reinserting him with 4:15 left in the half. Once he reentered the game, there was no doubting that he was the best Sixer on the floor.

Embiid blocked Avery Bradley's shot 19 seconds later. He closed out his scoring with a pair of foul shots with 9.6 seconds left in the half.

"I thought I did better defensively," Embiid said. "Offensively, that's going to come. But defensively that was one of my goals, and I think I did better."

The Sixers were focused on getting him used to the pace of the game, feeling the emotion of playing, and getting in-game conditioning.

Embiid said the next step is watching film and learning from his mistakes. He admitted that the Celtics messed him up when they started double-teaming him.

"I was like, 'That's my first game. Second quarter. Y'all really going to double-team, first game, second quarter?' " Embiid said.

Dario Saric, T.J. McConnell, Jerami Grant, and Brandon Paul were also impressive.

Paul finished with a team-high 15 points in a reserve role. McConnell added 13 points and four assists, while Saric had 10 points, six rebounds, two assists and four turnovers in his much-anticipated Sixers debut. He made 2 of 3 three-pointers. Grant also had 10 points.

Boston was paced by Terry Rozier's 12 points.

But this night was all about Embiid.

He had bone-graft surgery to repair the navicular bone in his right foot in August 2015. The former Kansas standout already had missed what would have been his rookie season after undergoing surgery in June 2014 to repair a stress fracture in the same bone. A setback in his recovery led to the second operation.

Sixers center Jahlil Okafor (knee), who missed the game, was said he was as happy as anyone to see Embiid on the court. The second-year player witnessed firsthand some of the struggles his close friend went through.

"I remember going to his house after I was drafted and then finding out that he wasn't going to be able to play with me last year, seeing the disappointment on his face and seeing him overcome it," Okafor said. "To be disappointed two years in a row to go through not playing and now he's finally here. So it's a great story, and I'm excited to see him play."

Sixers reserve guard Nik Stauskas left the game at halftime with a left hamstring strain and didn't return.

"I'm good," he said after the game. "We will see. I don't know I'll feel tomorrow."